IIIT

No, it is not a normal practice in JoSAA but due to pandemic there were relation for past year, there is no chance that they will continue with that.

You can expect some lower NITs with lower branches also you have good chances of getting decent IITs with good branches so don't give up and participate actively in JoSAA.

No, you can not get admission into any college with your JEE Main rank, even under the Schedule Caste category without a home state quota. However, this is just an estimate based on the previous year's cutoff, and if seats are available for this year, you may also get admission at the National Institute of Technology and Indian Institutes of Information Technology. It also depends on domicile and gender. For more details, you may the Shiksha JEE Main college predictor. (https://www.shiksha.com/engineering/jee-main-college-predictor).

No, you are not eligible as the minimum eligibility is 75% in 10+2. DVD.

With 17200 rank, it's not possible to get into IIT Delhi for General Category Students. With 41200 rank you can get Mechanical Engineering at NIT Delhi and may get Electrical Engineering by CSAB-2.

For General Category Students:
Open - 10052 ; Close - 18622 ( Gender - Neutral )
Open - 11711 ; Close - 24554 ( Gender - Female )
This is of 5th round of Josaa Counseling 2022.

No, you won't be able to. JEE Main Cut off depends on several factors such as:
Total number of candidates appearing in the JEE Main entrance exam. Total candidates applied for admission in UG or PG degree courses in NITs. Total seat intake and difficulty level of the examination. As you are from the ST category, according to previous year trends the qualifying mark would be near "43-46", Keep eye on the rankings.

You will not be able to get a seat in IIITD.

For taking admission in IIT after drop is that you should not have taken admission in any of the IIT course previous year. There is not an issue if you take admission in NIT or IIITs and next year, appear for JEE Advanced (meeting all other eligibility criteria). You should must visit the FAQ section on JEE Advanced website where they have answered like almost all of the different scenarios for students. Hope it helps then please upvote.

IIIT Surat is shifting to new campus in July / August
due to this reason the answer below becomes obsolete , not much of help now
REVIEW AS OF DECEMBER 2019
I am currently in first year of IIIT Surat,Computer science branch, and here is the overview of my college so far-
CAMPUS AND INFRASTRUCTURE
Currently , our campus ai not ready so our college is functioning within SVNIT , and shares all of its campus resources like classrooms ,labs,sports facilities,gym,student clubs, hostels etc. However , we do have our own admin building, computer labs and electronics labs have been setup separately recently in this year itself .